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Re: Hacking the Xaar 128 printhead

Posted: Thu May 28, 2020 9:32 am
by Sqo-86
Sup, guys!
It is really interesting topic, a lot of useful information for beginner, many thanks to all!
During my study i plan to use diferent types of binders, such as solvent- and water-based inks, as well as uv-curable inks.
I previosly chose the Xaar-128 for hardware design, but after reading this topic i realized that this type of printhead is not as versatile as I thought.
Could you give me pls some suggestion as to what type of printhead I should choose for my research and what material do you think is most suitable for xaar-128?

Re: Hacking the Xaar 128 printhead

Posted: Sun May 31, 2020 10:43 pm
by notsure
The Xaar heads like the 128 are shared wall types that can NOT use conductive fluids like water. The PZT connections are in the fluid chamber so they come in contact with any fluid that is in the chamber.

Since they are shared wall they are also not single pass heads. Every other nozzle is fired at one time.
https://www.youtube.com/watch?v=SmrdrCN_7No

These heads must be stitched to be able to print higher DPI in a single pass vs raster scanning.

The 128 also has no integral heater so printing of UV inks will require the use of an external heater but the printhead can only handle an external temp of ~55C max. The heads will also self heat through use. Some of the heat is carried away by the fluid jetted. So this excludes the use of most off the shelf UV inks.

The heads require a slight negative pressure supply, usually ~few hundred negative pascal. An easy way to do this is to have the ink supply just a few inches lower than the printhead.

They are a very popular inkjet printhead mainly used in solvent and oil ink applications. They may be used for a polyjet printer and UV cured fluids but they have to be formulated for the 128. http://bucktownpolymers.com/

Re: Hacking the Xaar 128 printhead

Posted: Mon Jun 01, 2020 4:41 pm
by notsure
To clear up the stitching of heads vs angling the heads for single pass printing I've attached a picture (difficult to find)
https://www.researchgate.net/profile/Zs ... d-9-mm.png

As the heads are angled the nozzle pitch decreases as does the print swath.

Re: Hacking the Xaar 128 printhead

Posted: Tue Jun 02, 2020 6:41 pm
by davidk
Many thanks for info!

Re: Hacking the Xaar 128 printhead

Posted: Wed Jun 03, 2020 6:44 pm
by notsure
Many thanks for reverse engineering this and the HP TIJ heads. Even under NDA the manufactures are stingy with specs. They want total control over the heads, fluids, fluid supply, printhead controllers etc.

Re: Hacking the Xaar 128 printhead

Posted: Wed Jun 03, 2020 6:57 pm
by davidk
Notsure, do you have experience with this printhead? I'm interested what inks did you supply to it.

Re: Hacking the Xaar 128 printhead

Posted: Thu Jun 04, 2020 3:02 am
by notsure
I've been using it since it came out. I make inks for it. I also have a UV cured water soluble support and several UV polymers for it to make a polyjet printer. You just can't use any conductive or water based inks with them.

Re: Hacking the Xaar 128 printhead

Posted: Thu Jun 04, 2020 3:08 am
by notsure
People here have tried UV inks with these heads and they don't work since the viscosity is too high near room temp. The off-the-shelf UV inks expect the heads to be heated to lower the viscosity of the ink, mine work at room temp.

Re: Hacking the Xaar 128 printhead

Posted: Mon Jun 08, 2020 9:55 am
by abbasrohanipoor
Hello every body
How do you do?

Re: Hacking the Xaar 128 printhead

Posted: Tue Jun 09, 2020 8:04 pm
by Romina
abbasrohanipoor wrote: Mon Jun 08, 2020 9:55 am Hello every body
How do you do?
Hi,
Would you please explain which materials you have used?